Field of the Invention
The invention relates to a memory, a manufacturing method thereof and an operation thereof, and particularly relates to a resistive random access memory, a manufacturing method thereof and an operation thereof.
Description of Related Art
A memristor is a two-terminal device, which uses electric field-induced resistance-switching (RS) to change a resistance state thereof. Since the change of the resistance state is non-volatile, the memristor can be applied to artificial neuromorphic synapses, fuzzy-logic devices and resistive random access memories (RRAM), etc.
The RRAM is widely applied in a non-volatile memory field. Since the RRAM has a simple crossbar array and is suitable for low temperature manufacturing, the RRAM has the best potential to replace the existing flash memory. Although the crossbar array architectures of the RRAM theoretically allows the minimum memory cell size of 4F2 (where F is the minimum feature size), and the low temperature manufacturing allows stacking of the memory arrays to reach an unprecedented integrated density, in a 1R structure (i.e. only one resistive element is included), an undesired sneak current may flow through an adjacent unselected memory cell to severely influence a read margin and limit the maximum size of the crossbar array. Such problem can be resolved by using an additional non-linear selection device to connect the resistive switching elements in series. Therefore, structures of one diode in collaboration with one resistor (1D1R) and one selector in collaboration with one resistor (1S1R) seem to have become main competitors of 3D stacked memory application.
However, when the aforementioned 1D1R and 1S1R structures are applied to the 3D crossbar array, it is liable to have a process problem, so that the above structures cannot be actually applied to the manufacturing process of the 3D memory. Therefore, to implement a non-linear resistive switching element without using an additional selection device becomes an important issue in development of the 3D memory with the RRAM.